There’s a wonderful command line utility on Macs called pmset. You can run the following command to see a log of what happens when your computer goes to sleep and wakes up…
pmset -g log
Using this, I was able to see the following entry that was slowing things down…
* Domain: applicationresponse.timedout - Message: Kernel cupsd com.apple.powermanagement.applicationresponse.timedout 30000 ms - Time: 4/4/11 11:52:59 AM EDT - Signature: cupsd - UUID: 1D806166-A5FA-498C-A769-8A29FB2A15F3 - Result: Noop - Response time (ms): 30000
That last line “Response time (ms): 30000” means that it was waiting 30 seconds for this process to finish!
Thanks to googling, I was able to find that you can access the CUPS Print System from your browser by going to http://127.0.0.1:631/jobs/. I deleted the old print jobs that the power management system was attempting to resolve on standby, and now my laptop goes into standby much more quickly.